Granted Patent
Utility
US 4,821,228 · App. 06/946,543
Method and apparatus for computation stack recovery in a calculator
Inventors:
William C. Wickes, Laurence W. Grodd
Patented Case
View Patent ↗
Granted: Apr 11, 1989
Filed: Dec 24, 1986
Inventors
William C. Wickes
Laurence W. Grodd
Assignee (at issue)
Hewlett-Packard Company, L.P.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.